Electrically actuable locking devices for furniture are described in DE 41 01 744 A1. In a first variant, a so-called spring catch with a catch bolt is fastened, as locking element, on a movable part of a piece of furniture, e.g. on a door or a drawer. The locking-element socket provided is a door opener latch, which is arranged on a stationary furniture part. A closed position or open position of the door opener latch for locking or unlocking the door or a drawer is achieved with the aid of an armature and an electromagnet.
This known locking device may be equipped either with an open-circuit door opener latch or with a closed-circuit door opener latch. Optional, switch-over open-circuit operation or closed-circuit operation is not possible.
In a further variant, the locking element provided is a locking bolt which, in the direction of its longitudinal axis, can be moved to a lower, open position and into a closed position with the aid of a drive. In the closed position, the locking bolt engages in a mating element, which is fastened on a stationary furniture part.
As a result of the design, the known locking devices can only be fastened in one position on the stationary and movable furniture part. Optional arrangement of the locking device in accordance with the different conditions and furniture configurations is not possible.
One object of the invention is to provide a furniture-locking device which can be actuated electrically and permits an arrangement which is adapted to the various installation situations, as well as, simultaneously, monitoring of the open state and locked state.
A further object of the invention is to provide a locking device which is intended for locking and unlocking two components, which can be moved relative to one another, and of which the design permits optionally closed-circuit operation or open-circuit operation.
The first object is achieved according to the invention by a locking device having the features of claim 1. Expedient and advantageous configurations form the subject-matter of the subclaims and are contained in the description of the figures.
An essential basic idea of the invention is that a locking element of defined design interacts with a locking-element socket which, for optional arrangement of the locking device, has two sockets for the locking element. According to the invention, the locking element provided is a locking pin and the locking-element socket provided is a locking slide arranged in a locking housing. The locking slide is of virtually cuboidal or cubic design and is arranged in the vicinity of an end side and of an adjoining housing wall of the locking housing, so as to ensure a vertical adjusting movement with guidance on at least one housing wall, in particular on a covering.
According to the invention, two introduction openings are formed in the locking housing and, in the unlocking position, these are aligned, or arranged congruently, with sockets of the locking slide, which adjoins on the inside.
If in each case one introduction opening and one socket, preferably a vertically arranged slot, for a locking pin is provided on an end side and on a front side of the locking housing and of the locking slide, which abuts on the inside, then account can be taken of the different installation situations in each case and the locking device according to the invention can be fastened as required on a piece of furniture or else on other lockable structures, such as safe-deposit boxes, left-luggage lockers or the like.
A locking position and unlocking position are achieved, once the locking pin has been introduced, by vertical adjustment of the locking slide. The locking slide is actuated by an armature/coil device. The locking slide is designed such that locking and unlocking operations can optionally be adjusted in accordance with the closed-circuit principle (unlocked when not supplied with current) and in accordance with the open-circuit principle (locked when not supplied with current).
The closed-circuit principle or open-circuit principle can be predetermined particularly advantageously by an armature of the electromagnet being "switched over".
According to the invention, for the purpose of monitoring the presence of a locking pin, an indicator element is arranged at the point of intersection, of the axes of the two introduction openings or of the sockets of the locking slide and, when a locking pin has been pushed in, to be precise irrespective of the introduction opening, said indicator element is displaced counter to a compression spring and actuates a switch in the process.
The switch is expediently a microswitch and is connected to a monitoring or alarm system, with the result that both the locked state, in which the indicator element is displaced downward counter to the force of a spring supported on the housing, and the unlocked state, in which the indicator element is forced by a spring to project into the socket, are registered.
The locking pin is designed in the form of a circular cylinder and projects approximately at right angles from a fastening flange with fastening openings. It is advantageous for the locking pin to be fastened releasibly in a cutout of the fastening flange and for the cutout to be designed preferably with a relatively large diameter, with the result that the locking pin can be displaced, in order to compensate for tolerances, and fastened thereafter. The locking pin is preferably provided with a frustoconical introduction region, in order to come into contact with the introduction opening when the tolerance region is being utilized.
The locking pin also has a locking groove, in the vicinity of the fastening-flange end, and an indicator groove, in the vicinity of the free end. With the locking slide displaced appropriately, the locking groove and the adjoining blocking surfaces engage behind the slot opening of said locking slide, with the result that it is not possible for the locking pin to be drawn out of the locking slide and out of the locking housing. This means that a locking position has been achieved.
The indicator groove serves for the engagement of the indicator element. For this purpose, the indicator element, which is designed virtually in the form of a circular cylinder, has an approximately hemispherical head region, which is designed to be virtually complementary to the indicator groove. By virtue of the engagement of the indicator element in the indicator groove of the locking pin, the indicator element acts, at the same time, as a latching element and thus also fulfills the function of a "latch-in ball".
The locking pin is advantageously provided with a front introduction region in the form of a truncated cone. The introduction openings in the locking housing are of complementary design and taper in the direction of the locking slide.
The locking housing is closed on all sides and has fastening openings at least in a base surface. The locking housing is usually fastened in a stationary manner on a piece of furniture, while the locking pin is fastened on the movable furniture part. However, it is also conceivable for this arrangement to be swapped round.
The locking slide is adjusted with the aid of an armature, which is of bar-like design and can be pivoted about a pivot axis. The armature is expediently designed as a single-arm lever. One or even two coils of an electromagnet is/are arranged in the vicinity of the pivot axis. A free end region of the armature is fixed, e.g. suspended, in complementary grooves, namely in an open-circuit groove or in a closed-circuit groove of the locking slide. Since fastening can be performed as required, it is possible to change over from closed-circuit operation to open-circuit operation and vice versa.
According to the invention, the second object is achieved by a locking device having the features of claim 14. This locking device, which is mentioned in the introduction, is defined in that the locking element provided is a locking pin and the locking-element socket provided is a locking housing with an electrically actuable locking slide, and in that, by virtue of setting the relative positions of interacting locking parts of the locking pin and of the locking slide, it is possible to set optionally open-circuit operation, in which the locking pin is locked when the actuating device has not been supplied with current, and closed-circuit operation, in which the locking pin is unlocked when the actuating device has not been supplied with current.
The possibility of optionally setting open-circuit operation or closed-circuit operation means that the necessary range of variants and types is reduced to a considerable extent. Setting can be carried out when the locking device is first fitted on components, furniture, safe-deposit boxes, left-luggage lockers, drawers and the like or else is straightforward to change over at a later stage as required.
Advantageous configurations of the invention are specified in the associated dependent claims.